The present invention relates to an air conditioning register that is used as an air outlet in an air conditioner, and regulates a direction of the air blown into a compartment.
In a vehicle such as a motor vehicle or the like, in order to display an operation of a device such as a navigation system, and a state of the device, there is a case that a display device is installed in a center cluster of an instrument panel. In recent years, in order to improve the visibility, the sizes of display portions (screens) of display devices have been enlarged. In the case that the display portion is arranged in a lower portion of the center cluster, the line of sight of the driver is shifted by a great distance when the driver shifts the line of sight from the windshield to the display portion. From this point of view, it is preferable that the display portion is arranged in an upper portion of the center cluster. For these reasons, a display portion 102 having an enlarged size is arranged in an upper portion of a center cluster 101 as shown by a solid line in FIG. 12, in recent years. A two-dot chain line in FIG. 12 shows the display portion 102 before being enlarged in size.
An air conditioning register 103 is arranged as an air outlet in an air conditioner in addition to the display portion 102, in an upper portion of the center cluster 101. Accordingly, since the display portion 102 occupies a large part in the upper portion of the center cluster 101, a place in which the air conditioning register 103 is arranged is limited. Therefore, in conventional, the air conditioning register 103 is arranged in both side portions of the display portion 102, as shown in FIG. 12.
However, since the air blowing from the air conditioning register 103 is directly applied to an arm of the driver gripping a steering wheel 104 in a layout of the air conditioning register 103 as mentioned above, there is a case that the driver feels bothered. Further, since the air blowing from the air conditioning register 103 is blocked by the arm of the driver, the air does not circulate within a passenger compartment. Accordingly, it is preferable that the air conditioning register 103 be arranged immediately above the display portion 102 in place of both side portions of the display portion 102.
However, if the conventional air conditioning register 103 is arranged immediately above the display portion 102 without any changes, the height of an instrument panel 100 including the center cluster 101 is increased in accordance with the arrangement. As a result, since an open feeling within the passenger compartment cannot be obtained, there is a case that an occupant feels oppressed and a confined. Accordingly, in order to suppress the height of the instrument panel 100, an air conditioning register 103 having a small vertical dimension have been installed above the display portion 102.
For example, Japanese Patent No. 3572480 discloses, as shown in FIG. 13, an air conditioning register 103 provided with a retainer 105, a fin group and a fin angle setting mechanism 114. The retainer 105 is constituted by a tubular body. A ventilation passage 106 is provided in an inner portion of the retainer 105. An air outlet 107 formed in a wide rectangular shape is provided in a downstream end of the retainer 105. In the retainer 105, a pair of side walls corresponding to a short side A of the air outlet 107 among four wall portions surrounding the ventilation passage 106 form a first wall portion 108, and an upper wall and a lower wall corresponding to a long side B form a second wall portion 109.
The fin group is constituted by three fins 111, 112 and 113 extending along the long side B of the air outlet within the retainer 105. The fins 111 to 113 are arranged along the short side A of the air outlet and spaced away from each other. Each of the fins 111 to 113 is supported at both ends so as to be tiltable with respect to the first wall portion 108.
Each of the fins 111 and 113 positioned in both ends in the arranging direction of a plurality of fins constituting the fin group is arranged so as to come close to the second wall portion 109. Each of the fins 111 and 113 is constituted by two members arranged along the ventilation passage 106. In other words, the fin 111 is constituted by an upstream piece 111a and a downstream piece 111b, and the fin 113 is constituted by an upstream piece 113a and a downstream piece 113b. 
The fin angle setting mechanism 114 sets an angle, that is, an inclination of each of the upstream pieces 111a and 113a and the downstream pieces 111b and 113b of each of the fins 111 and 113. The fin angle setting mechanism 114 holds the downstream piece 111b (113b) of the fin 111 (113) positioned in a tilting direction of the fin 112 in a direction parallel to the second wall portion 109, and tilts the upstream piece 111a (113a) in the same direction as the fin 112 in synchronous with the tilting motion of the fin 112, at a time when the fin 112 is tilted. Further, the fin angle setting mechanism 114 tilts the downstream piece 113b (111b) of the fin 113 (111) positioned in an opposite side to the tilting direction of the fin 112 in the same direction as the fin 112 in synchronous with the tilting motion of the fin 112, and holds the upstream piece 113a (111a) in a direction parallel to the second wall portion 109.
For example, as shown in FIG. 14, in the case that the fin 112 is tilted so as to be higher toward a downstream end, the fin angle setting mechanism 114 holds the downstream piece 111b of the fin 111 in a direction parallel to the second wall portion 109, and tilts the upstream piece 111a in the same direction as the fin 112. Further, the fin angle setting mechanism 114 tilts the downstream piece 113b of the fin 113 in the same direction as the fin 112, and holds the upstream piece 113a in the direction parallel to the second wall portion 109.
In accordance with the air conditioning register 103 described in Japanese Patent No. 3572480, it is possible to resolve a problem generated in the case of simply making the air conditioning register thin, that is, a problem that an interval between the fins 111 to 113 becomes narrow and it is hard to secure an air flow passage. However, as long as the air conditioning register 103 described in Japanese Patent No. 3572480 employs the structure mentioned above as the fin angle setting mechanism 114, the upstream piece 111a (113a) of the fin 111 (113) positioned in the tilting direction of the intermediate fin 112 is tilted in the same direction as the fin 112 in synchronous with the tilting motion of the fin 112. In accordance with the tilting motion, a space 115 in which the height is enlarged toward an upstream end is formed between the second wall portion 109 and the upstream piece 111a (113a), as shown by a two-dot chain line in FIG. 14. Since the space 115 forms an air drift, the air enters the space 115 so as to form eddy currents. As a result, there is a risk that a noise is generated. Further, there is a risk that a pressure loss is enlarged at a degree that the air flows into the space 115.